[cats_five]

You can Look here, this in Spanish.
Conversión de JPEG a RAW. Exprimir las compactas al máximo

Sorry but there is absolutely no way of getting from a JPG back to the RAW. The camera's image processing engine will have done a lot of work and none of the necessary information to undo it is recorded, nor can the bits of information that have been discarded be recovered.

[eddie1960]

but too my surprise, a pro wedding photog told me he only uses jpegs as he does not have time to convert his raw images into a jpeg format. Go figure.

That doesn't necessarily surprise me A wedding photographer and second shooter can easily shoot 2-3000 pictures in a day. So even though there may be some incorrectly exposed good shots he should easily be able to assemble a large enough portfolio to satisfy the wedding party. Trying to do post on that many pictures is nuts (I've had event weekends where I've averaged 800-1000 a day and the post was overwhelming even using batch processing in Bridge at the time or lightroom now)
There are also Wedding guys still shooting film for it's look (to some great effect from examples I've seen) they usually have a second shooter for all the candid stuff and do all the artsy stuff themselves with great care and less exposures on film....then it's off to the lab where they get it processed and rough scans or proofs for the initial edit process and just either do high res scans themselves or have a specialist at the lab do them for them(more likely they are charging enough to cover this if they are good)

[iClick]

I was surprised to find though, that the RAW file is basically the same size no matter what resolution you use... 2 MP, 6 MP, 10 MP, etc. So if you shoot in RAW only you don't gain any more shots on your card.

[RioRico]

I was surprised to find though, that the RAW file is basically the same size no matter what resolution you use... 2 MP, 6 MP, 10 MP, etc.

That's because those 2-6-10-14mpx settings are for JPGs, nor for RAWs. The RAW file is ALL the data from the sensor at the moment of exposure, filtered only slightly. That's why it's called RAW -- it ain't been cooked yet! All the camera settings -- WB, image size, sharpness-contrast-saturation etc -- are your way of telling the cam's little brain how to produce JPGs. Those settings are included in the RAW file, as is a thumbnail JPG using those settings, and they carry into a RAW processor (I use PentaxPhotoLab3) as the image's defaults. But you can't tell the camera to truncate the data and make a smaller-resolution RAW file. If you could, it wouldn't be RAW any more, would it now?

[Lowell Goudge]

Just a dumb idea here but what if you increase color depth from 8 bit to 16 bit and then resize to double the pixel count. As a minimum it should make the resize smoother although the base data was only 8 bit there should be some interpolated points that are more resolution in terms of color depth

[jpette]

@bobby_navy:
Oui ,vous avez raison, il est possible d'extraire le Jpeg qui est inclus:encapsule dans un fichier PEF (d'ou d'ailleurs le cote non malin de certains d'utiliser la fonction raw+jpeg 12m *)
Pour infos (poiur tous) dans un raw vous pas un mais 3 jpegs
1 vignette en 160x120 pixels de 7ko environ la commande dos est:
exiftool -b -ThumbnailImage _IGP6003.PEF > thumbnail.jpg

2Eme vignette, est une image de 640 x 480 pixels, mais de tres mauvaise definition qui fait 20 ko
exiftool -b -PreviewImage _IGP6003.PEF > preview.jpg

et ce que vous demandez, le jpeg taille reelle (pleine taille et une etoile) qui est ici
exiftool -b -JpgFromRaw _IGP6003.PEF > FullSize.Jpg
sort l'image complete a 1,23Mo en 4288x2848 a Partir du Pef

Ici j'ai pris le nom de fichier en "dur" pour simplifier l'exemple, apres vous pouvez meme traiter
par lots etc et utiliser %1 %2 comme d'habitude.

Et il ne s'agit pas ici d'un dematricage, mais juste d'une copie de blocs (le jpeg contenu)
aévec un simple batch et un vieux pc avec cette mthode vous "traitrez" 3600 pefs en une
heure, ce qui est evidemment impossible meme avec un quadruple opteron , si vous euvrez avec un dematricage
Et le programme a recuperer est evidemment "exiftoll" (rechercher goggle)

En esperant avoir bien repondu a votre demande et esperant ne pas m'etre trompé
(avoir bien compris votre demande)

Information importante: attention lorsque vous utilisez, compensation des ombres et ddr mode, le pef
peut, ne pas exprimer la realitée d'exposition du jpeg que vous voyez, faites attention a ceci

cordialement, jpette

[cats_five]

@bobby_navy:
Oui ,vous avez raison, il est possible d'extraire le Jpeg qui est inclus:encapsule dans un fichier PEF

bobby_navy asked to do it the other way round - get back to the PEF from the JPG - which cannot be done.